More consistency checking for relationship group records

Added the following checks:
o RelationshipGroupRecord has invalid rel type id
o RelationshipGroupRecord has invalid next pointer
o RelationshipGroupRecord chain is unsorted
o RelationshipGroupRecord refers to relationship that is not in use
o RelationshipGroupRecord refers to relationship that is not first in its
  chain
o RelationshipGroupRecord refers to relationship that is of a different
  relationship type than its group
Merge pull request #2035 from tinwelint/2.1-cc-relgroups

More consistency checking for relationship group records
HOME is now set in the build configuration/ machine itself
Tie USING PERIODIC COMMIT to LOAD CSV
Ignore doc tests for PeriodicCommit until we get the doc update in